#include "UdpClient.hpp"
#include <iostream>
#include <string>
#include <cstring>
#include <sys/types.h>          
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>

#include "Common.hpp"


//udp_client serverip serverport
int main(int argc,char* argv[])
{
    if(argc!=3)
    {
        std::cerr<<"Usage:"<<argv[0]<<" serverip serverport"<<std::endl;
        Die(USAGE_ERR);
    }

    std::string serverip=argv[1];
    uint16_t serverport=std::atoi(argv[2]);

    //1.创建socket
    int sockfd=::socket(AF_INET,SOCK_DGRAM,0);
    if(sockfd<0)
    {
        std::cerr<<"socket error"<<std::endl;
        Die(SOCKET_ERR);
    }

    //1.填充网络信息
    struct sockaddr_in server;
    memset(&server,0,sizeof(server));
    server.sin_family=AF_INET;
    server.sin_port=::htons(serverport);
    server.sin_addr.s_addr=::inet_addr(serverip.c_str());

    while(true)
    {
        std::cout<<"Please Enter# ";
        std::string message;
        std::getline(std::cin,message);
        //client必须有自己的端口和ip,但客户端不需要自己显示的调用bind,
        //而是客户端首次sendto消息时，由os自动进行bind
        // 1. 如何理解client自动随机bind端口号？ 一个端口号，只能被一个进程bind,防止本地客户端冲突
        // 2. 如何理解server要显示的bind？服务器的端口号，必须稳定！！必须是众所周知且不能改变轻易改变的!
        int n=::sendto(sockfd,message.c_str(),message.size(),0,CONV(&server),sizeof(server));
        (void)n;

        struct sockaddr_in temp;
        socklen_t len=sizeof(temp);
        char buffer[1024];
        n=::recvfrom(sockfd,buffer,sizeof(buffer),0,CONV(&temp),&len);
        if(n>0)
        {
            buffer[n]=0;
            std::cout<<buffer<<std::endl;
        }
    }
    return 0;
}